The present invention relates generally to computer controlled train brake systems and more specifically to a hostler control of a computer controlled train brake system.
Computer controlled train brake systems include electropneumatically controlled valves to control the train automatic brake system and the independent locomotive brake system. This is generally done by controlling the pressure in the train brake pipe and the locomotive independent application and release pipe. A typical example of such systems is the CCB and CCB II available from New York Air Brake Corporation, a Knorr-Bremse subsidiary of Watertown, N.Y. and as illustrated, for example, in U.S. Pat. No. 5,249,125.
Computer controlled train brake systems as well as pneumatically controlled train brake systems include a hostler stand which is a control stand located at the rear of the locomotive to provide the operator with the ability to control the locomotive throttle and independent brake for yard moves and train make-up. The presently available hostler stands have been completely manual or completely electronic in the control of the brake system, with the transfer to and from hostler control obtained by a manual set-up process only, i.e., cut-out cocks. Prior computer controlled train brake systems, when being switched into the trail mode, shut down or go into an idle mode, and relinquished control to the hostler stand. The hostler stand operates independently of the computer controlled brakes and manually-pneumatically operate the independent brake of the locomotive. The throttle is also independently controlled through the throttle control at the hostler stand.
The present hostler control of a computer control train brake system combines the computer control of the train and locomotive brake system with manual control during hostler mode to provide soft and safe operation of the vehicle. Electric and pneumatic interlocks provide efficient and safe transferring of the controls between the computer control brake system and the hostler control portion. The computer control train brake system includes an electropneumatic brake controller which automatically applies the independent brake once the hostler lead mode is determined. Next, the brake controller charges the brake pipe to release the train brakes. Control of the independent brake is transferred to a pneumatic independent brake control valve at the hostler stand after the brake pipe has been charged sufficiently to fully release the train brakes. The brake pipe is charged or the train brakes are released only after the independent brake application has reached a predetermined value. The independent brakes are applied by charging an independent pipe and providing pressure to the brake cylinder. Charging the brake pipe includes charging a reservoir, for example, an equalization reservoir of a brake pipe control valve, and charging the brake pipe using the brake pipe control valve. The brake pipe is charged only after the reservoir has reached a predetermined pressure. After the independent brakes are applied to a given value, the brake pipe is charged only upon receipt of a brake pipe charge command from the operator.
Applying the independent brakes and charging the brake pipes are not initiated if the train is moving or if an emergency brake is active. If emergency brake is active, or the mode is changed from the hostler trail mode or a penalty is received, the independent brake is applied, if not already applied, the brake pipe is discharged to apply the train brakes and subsequently the independent brake is released. The brake pipe is discharged first at a service rate and then at an emergency rate. For a hostler penalty state, a predetermined independent braking is set using the brake controller. Independent brake control is transferred back to the independent brake control valve upon removal of the hostler penalty state.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.